First, use a citrus zester on the lemons until you have 1 tablespoon of zest and set it aside. Then cut the lemons in half and juice them until you have ½ cup lemon juice. Set the juice aside.
Preheat the oven to 350°F and lightly oil a 9.5'' (2.75 qt) or 8'' x 8'' baking dish.
To make the crust, take a medium sized mixing bowl and add the almond flour and salt and mix together. Then add honey and melted butter, using a fork to mix together until it becomes crumbly in texture.
Pour the mixture into the prepared baking dish and use the back of the fork to press the crust into the dish until it is firmly packed in. Bake on the middle oven rack for 15-17 minutes or until lightly browned.
While the crust is baking, make the lemon curd. In a little bowl, mix together the corn starch and cold water until the starch dissolves. Set it aside.
Then crack 4 eggs into a medium saucepan and use a wire metal whisk to lightly whisk the eggs. Add in the lemon juice and honey and place the saucepan over the stove on low heat. Whisk the ingredients together for about 3 minutes until they are combined.
Next, add the starch mixture and the lemon zest. Continue whisking for another 10-12 minutes while gradually raising the stove to medium heat. Be careful not to cook the eggs. The curd is ready once it becomes thick.
Pour the lemon curd into the baked crust and bake for about 25 minutes or until the curd no longer jiggles when gently shaking the baking dish. The curd will continue to set as it cools. Allow the lemon bars to cool completely before serving or refrigerating.